April 22, 2010

Fine Tuning Arguments

Suppose someone is rolling a set of two dice. He rolls a double six – something with a one in 36 chance of happening. Which is more likely, that the person rolled a set of regular dice and just got lucky, or that he rolled a special set where both dice have just sixes on all faces? (Let’s assume you can’t see any but the sides that are on the top.) You might think that since a regular set would produce a double six in only one out of 36 attempts, he is more likely to have rolled the trick dice with just sixes. But after a moment’s thought you would probably realize that was wrong. With just one roll of the dice, you would have no way of knowing. The person might have been rolling the dice all day, and you just happened to come along at the exact time that he rolled the double six. Of course, you could stay and see if he rolled the dice again, and if he kept getting double sixes then you would suspect there was something fishy going on. But with just one roll, there is no way you could tell. You wouldn’t have enough information.

The same would be true if the guy rolled three dice and got three sixes, or four dice and got four sixes, or five dice… etc etc. If he only called you over to look when he’d got all sixes, you wouldn’t know if his roll had been especially lucky, or if he had spent hours rolling other combinations, and only called you to look when the result was all sixes. No matter how many dice he rolled at once, or how high the apparent odds against it happening by chance, you wouldn’t know he was cheating just by looking at the result of one roll. You also wouldn’t know how many other people are rolling dice at the same time, but who are keeping quiet about it because they rolled uninteresting combinations. At the very least, you would need to see a few consecutive rolls from this one guy before you could form any conclusions.

It seems to me that fine tuning arguments are similar to the dice rolling guy. The fine tuning argument is this: the odds of “rolling the dice” to get, by chance, a universe where life can exist, are so low that the universe must have been designed. But the objections to this are the same as with the dice rolling guy: unless we know how many universes there are, and how many big bangs there have been, we can’t know if our particular universe is very unlikely to have occurred by chance or not. There might be millions of universes. And if there are a very large number of universes, then the odds of getting one tuned for life, are very good. And in that case, there are good odds that in at least one of the universes tuned for life, there evolved intelligent people like us who remark that this universe looks fine tuned for life.

Now, you may say, we don’t have proof that additional universes exist, or that there have been several big bangs. And I say that’s not my problem, it’s the problem of those making the fine tuning argument. If fine tuners are claiming that the odds of getting a universe suitable for life are extremely low, then it’s up to them to show that this is the only universe that exists or has ever existed. Their calculations that show the incredibly low probabilities of a universe suitable for life, assume there is and has only ever been one universe. Why is this? Because to get the probability of getting any universe tuned for life, they have to multiply their probability of getting one universe tuned for life by the total number of universes. They never do this – which means they are implicitly multiplying by one universe. So, before we accept their claim, they first have to demonstrate that there really is only one universe. It’s their claim, remember? They have to justify all parts of it, not just the bits they like. So as part of their own calculation, they must demonstrate that there is only one universe. As far as I know, no one has ever done this.

I have heard some say that multiple universes violate Occam’s Razor – one universe is “simpler,” they say. But this argument misinterprets Occam’s Razor. Occam’s Razor doesn’t say choose the simplest – if it did then “Goddidit” would be the answer to anything, because Goddidit is simple. Occam’s Razor actually says don’t make up unnecessary assumptions. We know that universes exist because we live in one. Unless there is a solid reason to think that there are no other universes apart from the one we see, it would be an additional assumption to insist without evidence that this is the only one. To be most generous to fine tuners, the best they can claim is that the assumption of many universes is an equal assumption to the claim that there can only be one, and so Occam’s Razor is a wash – you can’t use it to choose one way or the other. The burden of proof is therefore still upon the ones making the fine tuning claim.

Of course, we don’t need multiple universes to reject fine tuning arguments. We don’t actually know enough to be able to calculate meaningful probabilities of getting, by chance, the so-called fine tuned constants of this universe. We can only examine one universe, and can’t really say for sure what would happen if the conditions were different. Fine tuning arguments are really just god of the gaps arguments – we don’t know why the constants look fine tuned, so we’re going to use god to explain the gap in our knowledge. Never a very productive way of trying to learn the truth about anything. Also, we don’t know what kind of life would have evolved if the universe was very different from this one. Life as we know it might not exist, but that wouldn’t mean that completely different life forms couldn’t evolve. Again fine tuning arguments say more about the lack of imagination in the people making the arguments than about the truth of the conclusions they are claiming.

But even if we ignore these flaws, the burden of proof is still with the fine tuners to demonstrate that this is the only universe that exists or has even existed (or at least, that there is only a small number). Until they do this, fine tuners are like the person pointing to the guy who just told you he rolled several dice and got all sixes, while failing to investigate all the other people in the world and throughout history, who have rolled dice but didn’t tell you the results.

Additional Reading

Physicist Victor Stenger has many other arguments against fine tuning, including simulated universes with very different values for the so-called “fine tuning” constants. He also states that multiverses are suggested by modern cosmological models.

Another way of disproving the claim is pointing out the number of possibilities for a game of chess to end. What are the odds for these chesspieces to be placed in this particular position on the board? Or, what about the odds you get this particular set of cards in a game of poker? In effect, the statistical reasoning you discuss would mean that getting these cards, or this endgame, is impossible.

The argument presented implies that the chance is so astronamically small, and therefor the above examples too prove these games (i.e. the hand you were dealt) are subject to Intelligent Design.

Occam’s Razor actually says don’t make up unnecessary assumptions. We know that universes exist because we live in one.

Okay. I'm with you so far...

Unless there is a solid reason to think that there are no other universes apart from the one we see, it would be an additional assumption to insist without evidence that this is the only one.

Oh, sorry, no, you went just the opposite way that I would have gone there.

What you're doing is taking the burden of evidence off the people who claim that completely unobserved---and possibly unobservable---universes actually exist, and you're putting it on those who accept the null hypothesis that the only universe we have evidence of is the only universe.

If the claim went the other direction, that for some reason the universe by its very nature must be singular, or something like that, then perhaps we would be adding an assumption. However, that assumption isn't necessary to think there is only one universe, because there is absolutely no evidence otherwise.

The invocation of an unknown, possibly infinite number of universes (the biggest objects that are even possible to exist) using as justification only speculative theoretical physics and with a complete dearth of supporting evidence seems to be the clearest violation of Occam's razor since "goddidit."

How do these other universes -- without any casual connections or observable consequences in our own universe -- differ from an invisible dragon in a garage?

We know universes exist because we live in one. We don’t know that invisible dragons exist.

What you're doing is taking the burden of evidence off the people who claim that completely unobserved---and possibly unobservable---universes actually exist, and you're putting it on those who accept the null hypothesis that the only universe we have evidence of is the only universe.

The burden should be with those who state that other universes are impossible. People who use fine tuning arguments are claiming that – otherwise their calculations do not give the improbable odds they are claiming.

The invocation of an unknown, possibly infinite number of universes (the biggest objects that are even possible to exist) using as justification only speculative theoretical physics and with a complete dearth of supporting evidence seems to be the clearest violation of Occam's razor since "goddidit."

You misunderstand Occam’s Razor. A large number of universes does not violate Occam’s Razor any more than two would. The question is, is it (a) impossible for other universes to exist – ie is there some rule that forbids other universes, or (b) can other universes exist? As I wrote, the most generous I could be to fine tuners is to say that Occams’s Razor can’t choose between (a) and (b), since both represent an additional so far unproven assumption.

To a sapling hanging onto life in the snow-driven side of a cliff, half way up a mountain, the whole world looks like it was fine tuned solely for it to exist in this very spot.

If it were sentient, it might go so far as to consider that the bird that dropped the original seed in that very crevice must have been an incredibly intelligent beast. How else would it have possibly known that the crevice would provide everything this young tree needed to survive?

"We know universes exist because we live in one. We don’t know that invisible dragons exist."

Then how come I burnt my arm in my garage last week?
I know you pseudofauxersatzskeptikkks will point to the blowtorch and gasoline that I was playing with, but it must have been an invisible dragon, Graeme Bird told me so.
And no, there were no GOATS ON FIRE nearby to cause my injuries!

If I roll a die 10 times, what are the odds they will all come out sixes: exactly the same odds as any other specific pattern occurring.

Looking at a sample of N=1, you can't really conclude the universe is fine tuned. You can't distinguish between fine tunefulness and the possibility that you hit the jackpot on your one and only roll of the dice. I don't think the concept of any other universes is needed to discount fine tuning position, the extra universes are an unneeded distraction to the argument. Improbable and impossible are not the same thing.

We're here and able to observer the universe, therefore it did evolve and unfold in such a way to allow us to do so, but that does not imply that it was fine tuned for our existence anymore than the dice were fine tuned to produce the sequence 6,3,1,4,6,1,2,5,2,& 4 when rolled ten times.

Knowing about a single universe (ours) only it is not possible to speak about probabilities based on frequencies. That is the problem with the "improbable" argument and fine tuning. There is no way to calculate probabilities and that is why they can not argue based on that probability.

In your dice example if you see an innocent kid playing with the dice, you would suspect that he is using ordinary dices. But if the guy is obviously a magician, you might predict even based on a single roll that he might use "fake" dices.

You should have preliminary information when calculating probabilities.

On Occam's razor: I've heard that a multi-universe hypothesis is more parsimonious because a single universe hypothesis would require inventing a physical law specifically to constrain things.

I don't know enough about cosmology to know if that's accurate, but I'd certainly agree with Skeptico based on my personal understanding that it's inappropriate to claim that you can shave off other universes at this point: Both hypotheses posit rules we can't yet observe.

The available evidence is that all universes have a 100% probability of supporting life as we know it. We don't know whether it is possible NOT to roll a six.

The fine-tuning argument would need evidence from other universes to show that it is even possible to have values other than the ones we have. They simply assume that conditions for life are improbable, and then posit a designer to create them. It is just another argument by assertion.

Well, I know that I am kind of stupid, but, it seems to me that all of these arguments are empty. If things were not as they are then we would not be here reading them on our computer screens. Since we are here, there is no reason why things should be any different than they are, is there? Unless, maybe, y'all think that some god had something to do with it. I don't.

The statement is, (a) it is impossible for other universes to exist – ie there is some rule that forbids other universes, or (b) other universes can exist. As I wrote, the most generous I could be to fine tuners is to say that Occams’s Razor can’t choose between (a) and (b), since both represent an additional so far unproven assumption.

I suppose I can agree with this. Both (a) and (b) do represent unproven assumptions. Occam's razor doesn't really apply to this situation. It applies to explanations of observed phenomena, but neither (a) nor (b) is explaining an observed phenomenon at all. They propose phenomena.

I would like, though, if you recognized that both these questions are additions on top of a null hypothesis---the universe exists---and we don't need to posit either (a) or (b). In your post and subsequent comments, you seem to (at least that's my reading) be proposing the false dichotomy that a person must accept either many universes or the impossibility of many universes. In fact, one need not do either.

Not really. I didn’t conclude that the process of dice rolling is likely to have occurred many times before. I concluded that you wouldn’t know if the dice had been rolled before or not. It’s a subtle difference. Fine tuners are assuming just one “roll of the dice” to get the universe we see. I’m pointing out that they haven’t shown why we should let them assume that.

Also, your link provides a specific rebuttal to the claim of fallacious reasoning:

…instead of being summoned into a room to observe a particular roll of the dice, we are told that we will be summoned into the room immediately after a roll of double sixes. In this situation it may be quite reasonable, upon being summoned, to conclude with high confidence that we are not seeing the first roll.

That’s actually a better analogy to the universe we see, and the consideration of whether this is the only one that has existed, or just the one that has life.

Flavin:

I would like, though, if you recognized that both these questions are additions on top of a null hypothesis---the universe exists---and we don't need to posit either (a) or (b). In your post and subsequent comments, you seem to (at least that's my reading) be proposing the false dichotomy that a person must accept either many universes or the impossibility of many universes. In fact, one need not do either.

Strictly speaking that’s correct. It’s possible that multiple universes could exist, but that there is only one. But it seems to me unlikely. If it is possible for a random quantum fluctuation to create a universe, then it seems to me you would need a reason that this had never happened a second time. What happened once would be likely to happen again. Regardless, fine tuners need to provide some reason for us to accept that there is only one universe – which is their implicit claim.

Skeptico,
This is sounding a lot like the macroscopic/microscopic evolution qualm creationists have.

They claim that microscopic evolution (small changes at the cellular level or within species) exists, but macroscopic (one species becoming another) doesnt. they make this claim without providing the mechanism by which this sort of change would be inhibited.

I'm with you that if we see one universe, without a specific limiting mechanism that would prevent another one from coming into existence, then we should assume more, not that this one is unique.

I wonder if the Anthropic Principle works in reverse. The past has to be probabilistically special for the observer to exist at all. Does that mean the future will inevitably become more and more chaotic?

I guess it depends. If we were to find complex life in other planets, it would mean our conditions are not so special.

I concluded that you wouldn’t know if the dice had been rolled before or not.

Yes, and it’s completely irrelevant because it doesn’t alter the likelihood that two sixes will turn up in any way. So why would you bring it up if you didn’t think that two sixes mean the dice might have been thrown before?

Also, your link provides a specific rebuttal to the claim of fallacious reasoning:

…instead of being summoned into a room to observe a particular roll of the dice, we are told that we will be summoned into the room immediately after a roll of double sixes. In this situation it may be quite reasonable, upon being summoned, to conclude with high confidence that we are not seeing the first roll.

Yes. And I never said anything that would suggest that I don’t know or agree. Please keep your strawmen to yourself.

Another problem appears to be that you seem to think rolling two sixes is something special when it is just as likely as rolling any other possible combination of numbers.

Suppose someone is rolling a set of two dice. He rolls a double six – something with a one in 36 chance of happening.

Just like rolling any other possible combination of numbers.

Which is more likely, that the person rolled a set of regular dice and just got lucky,…

How exactly did he get ”lucky“? Again, rolling two sixes is just as likely as rolling any other possible combination of numbers.

…or that he rolled a special set where both dice have just sixes on all faces? […] You might think that since a regular set would produce a double six in only one out of 36 attempts,…

Once again, the same applies to every other possible combination of numbers.

…he is more likely to have rolled the trick dice…

Would you have said the same thing if he had rolled any of the other possible combinations of numbers that are just as likely to show up? Why or why not?

But after a moment’s thought you would probably realize that was wrong. With just one roll of the dice, you would have no way of knowing. The person might have been rolling the dice all day, and you just happened to come along at the exact time that he rolled the double six.

Would you have said the same thing if he had rolled any of the other possible combinations of numbers that are just as likely to show up? Or would you have thought that it might just as well have been his first roll? Why would this be different with two sixes?

Yes, and it’s completely irrelevant because it doesn’t alter the likelihood that two sixes will turn up in any way. So why would you bring it up if you didn’t think that two sixes mean the dice might have been thrown before? [My bold.]

the fallacy of concluding, on the basis of an unlikely outcome of a random process, that the process is likely to have occurred many times before. [My bold.]

Note, “is likely.” You just changed the inverse gambler’s fallacy from “is likely” to “might have.” Sneaky. Did you think I wouldn’t notice the switch? Of course they might have been rolled before. Or they might not. I never said it was likely.

And it’s not irrelevant because if there were several rolls, and yet you only get to see the outcome of the roll that produced the double six, the odds of seeing a double six would be greater than if there was just one roll. As I explained in my post, the fine tuners are assuming (by analogy) a double six on just one roll (which would be a low probability), but they haven’t shown that there was just one roll, therefore they can’t assume a low probability.

Yes. And I never said anything that would suggest that I don’t know or agree.

Yes you did. You said I had just committed the inverse gambler’s fallacy. The above reasoning, including from your own link, explains why it wasn’t. So please explain how you can agree with the rebuttal, while still saying I committed the inverse gambler’s fallacy.

Please keep your strawmen to yourself.

Pretty funny for someone who argues using a straw man version of the inverse gambler’s fallacy, and a straw man version of what my argument actually was.

Another problem appears to be that you seem to think rolling two sixes is something special when it is just as likely as rolling any other possible combination of numbers.

No I don’t. It’s just an analogy to the fine tuning argument, where only (by analogy) the double six is “lucky” (ie there is life). Grow up.

This is rather as if you imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in - an interesting hole I find myself in - fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, it's still frantically hanging on to the notion that everything's going to be alright, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise.

Hmmm, dice are nice, but I have another story that I've always used to explain this same principle:

What if I told you that there is someone in the stands of a huge sporting arena and they could blindfold themselves and throw a coin out onto the field only to have that coin fall perfectly into a mouthwash cup in the middle of the field?

Pretty unlikely, right?

Now what if I add the fact that all 40,000 seats are full of people trying this exact same thing and each of them has a bucket of 5,000 coins?

It suddenly seems more likely that ONE of those coins will make it in the cup, doesn't it?

Not to say your example doesn't work, but many people seem to be caught up in comparing the dice to each other or finding other ways to get hung up on some detail with that example. Mine seems to avoid some of those issues. (Not that people won't find a way to fight against this either...oh well. It was worth a shot!)

You’re right Ryan, and that’s the reason why Tom is wrong when he says that rolling a double six is not a special combination. A 12 (along with a 2) is the least likely roll, with only a 1 in 36 chance. The most likely roll is 7, with a 1/6 chance – six times more likely than a 12.

Actually that wasn’t the point. The point was that I had selected the double six (arbitrarily) as the number to represent the supposed long odds claimed by the fine tuners. So by definition, we were looking for a double six. That's why I didn't bring that up in my reply yesterday - it's a bit of a distraction, and Tom has already wasted enough time on distractions. But I still think it funny that as well as being incapable of understanding a simple analogy, and relying on straw man arguments, he also doesn’t even understand the dice rolling odds that he presumes to lecture me in.

Big Al, I'm not sure we can say they "can't" exist - just that we have no evidence that they can. That was my point above - the only universe we have evidence for is the one we're in. We can speculate about changing constants as much as we like, but without evidence that they can actually be different, it isn't much of an argument.

I have some problems with the fine tuning argument and also with the question of odds/ probabilities/ chances used as a "proof" for an inteligent designer.

As I understand it (correct me if wrong), the universe is always evolving and while it continues to expand the resulting environments in our galaxy will be completly hostile to life as we know it today.

The "fine tuning" is presented as a clever deffinitive outcome of a smart "guy" that allows for our form of life to exist, but in fact our current-moment biased view is only one picture of infinite temporal steps in a changing universe. We could not have existed here before our time and will pretty likely disapear at the next supernova explosion of the sun.

If the universe was "designed", then apparently only to host our life form for a short span of time. That's inteligent?

The radio is "fine tuned" now, but travelling in time we are progressing to other stations where our music will not be played and the coming cosmic noise can be heard today through radio-Hubble.

As to the odds:

Just look at each current unique existence of every single one of the 6,5 billion persons running around:

Every one's biography is the result of generations and generations of adding up of (im)probabilities, that when multiplied each in retrospective would be, i dare to affirm, less probable than the current "fine tuned" state universe.

For instance: had my grand grand grand grand father not offered that apple to his future wife that rainy day of 1823, and had he not chosen the only wormless fruit of the whole tree, and had he not left his house 1/2 hour later than normal because he was listening to his siter, who surprisingly did not die of influenza a year before, playing the piano, then I wouldn't be here. And so on with infinite scenarios.

Like with the fine tuned universe, I would need to conclude that this designer is acting in every microseceond in the lifes of every single person to lead to a pre-determined fate.

My existence then as a fact is so absurdly improbable that I should not even dare to affirm I exist without the grace of the all fate watch-maker that had everything tuned to have me writing here today (denying of him).

But the fact that the chances of something happening are absurdly improbable, does not exclude that event from taking place.

My chances of winning the lottery saturday are minimal - 1 to 14 million- and to be able to make this statement (minimal possibility)demands that we are capable of accounting for all combinations possible. Are we really able to do that regarding an universe that we barely comprehend?

It seems that code of the life- safe-vault was cracked by attempting to go brute-force through all numerical possibilities. The numbers before and after our current 38 left-15 right- 42 left are worthless.

BTW. Almost every saturday there is one that has the 6 of 49 correct. Why not me?

Yojimbo, we're actually in agreement. I was illustrating the futility of such an approach.

As you say, we only have first-hand experience of one universe and one set of laws, and we don't even know if others exist yet.

My feeling is that if we have a multiverse, there may be all kinds of sets of laws, some compatible with life and some not. The anthropic principle implies we shouldn't be surprosed to find ourselves in one of the universes that is.

Or, to put it another way, even if you shuffled the cards every 10 seconds without a single break, it would take you 25 million billion billion billion billion billion billion years to get that particular order again.

That’s about 1.8 million billion billion billion billion billion times longer than the entire universe has existed.

By any accounts, that’s a pretty unlikely thing to have happened. And yet, you managed to get that particular order the first time you randomly shuffled the cards. How was that possible?

The reason is that, if you have a pack of cards, then they HAVE to be in one particular order, so an event of “vanishingly small probability” HAS to occur whenever a pack is shuffled.

And that’s all you can say about the universe – because the universe exists, it HAS to have certain physical constants. Each particular combination of physical constants may be extremely unlikely to occur, but, just as a randomly shuffled pack of cards must produce an extremely unlikely outcome, so too a “randomly shuffled” universe.

Unfortunately, it's not quite that simple, Grumbly1. If you shuffled the deck thoroughly and all the cards came out in perfect card and suit order, that would be remarkable, and your jaw would probably hit the floor. The vast majority of hands will not be in any predetermined order and will therefore not be remarkable, even though each particular arrangement of cards on its own is no more probable than the aforementioned one.

The believer in fine tuning will liken all the "dross" hands to the possible universes that couldn't support life, and point out that ours is like the special case with all the cards in a specific order.

Richard Dawkins says that the Matterhorn is just a jumble of rock no more or less likely than any other, but that we have pre-defined its shape as notable. Therefore, if any other random jumble of rock were to spontaneously rise up to resemble it exactly, that would be truly remarkable - indeed, I might have to reconsider renouncing my atheism. It's the equivakent of the sorted deck.

I absolutely agree with you Big Al that a lot of believers in fine tuning (sadly) don't understand my explanation

They tend not to “get” it for 2 reasons:

1. Most people don’t really understand probability theory (or stats in general for that matter) – on a simple level, you can see this in the fact that many people can’t get their head around the fact that 1,2,3,4,5,6 has as much chance of coming up on the lottery as a seemingly “random” set of numbers (eg. 42, 23, 9, 15, 31, 25)

2. People tend to be very “specio-centric” ie they tend to think of humans as being something special, and therefore human life is the natural outcome of the evolution of the universe.

As you state, they seem to think that the current universe is so perfectly ordered that it must be like having the 52 cards come out in the exact suit order and this leads them to conclude that something must have “fixed” the deck of cards.

It’s a very arrogant view of the universe on the part of humans, caused by the fact that for 99% of human history, we knew virtually nothing of the universe outside of our own immediate environment.

To use one more analogy:

If you’d never seen a pack of cards before and someone gave you a pack that had been shuffled into a completely random order, you would have nothing to use as a reference and you might think that the order of cards that you had was something special.

It would only take someone else to show you their pack of cards, in a completely different order, for you to realise that yours wasn’t so special after all.

Of course, even if you saw another pack of cards, you might still think yours was special, particularly if you were originally given your pack of cards by someone you respected (eg a parent or a village elder) and the had told you countless times that your pack of cards WAS special.

Unfortunately, we are the situation where we only have one visible universe, and we have been told for thousands of years by people we “respected” that we are special and so many people continue to assume that we are something special and our universe has been "fixed" or "fine-tuned".

Their calculations that show the incredibly low probabilities of a universe suitable for life, assume there is and has only ever been one universe. Why is this? Because to get the probability of getting any universe tuned for life, they have to multiply their probability of getting one universe tuned for life by the total number of universes. They never do this – which means they are implicitly multiplying by one universe.

Sceptico, your math is wrong there. You wouldn't multiply with the total number of universes, as that might result in a "probability" higher than 1.

Correct math:
You subtract the probability of any universe tuned for life from 1 and then put that number to the power of total number of universes.

I don't give a damn about life in the Universe. I'm just trying to figure out the odds of stumbling across the most lame, nonesensicle piece of dribble ever written while at 12:45pm on the west coast of Canada on the 20th of October in the year 2010, not to include the fact that it's sunny outside without a cloud in the sky. The answer is simple. It's 100% because it happened. As improbable and unlikely as it seems, it happened so chance no longer enters into the equasion. End of story.

I agree with you that the Fine-Tuning argument is flawed. But I don't agree with your reasoning. Multiple universe do indeed defy Occam's Razor. We have no proof that they exist, and the burden is always on the one making the positive claim to prove it, not the negative claim. If we as Secularists keep on making arguments like this, we'll become just like the Theists.

Fine-Tuning is a God-of-the-Gaps arguments. The use of the Bayes Theorem to prove it is also flawed in its assumptions. But, other than pointing out that other constants may give us different life-forms, I can't think of a good argument against it. I can't prove that other constants would yield different life-forms. It's kind of frustrating.

Fine-Tuning is such garbage, but for some reason, I just can't come up with very good arguments against it. The rest of Intelligent Design is easy to break because of its logical fallacies, but Fine-Tuning is pretty clever. It's gonna take some thinking to break this one.

I dealt with your objection in my original post. Fine tuners are making a positive claim, namely that there is only one universe. They haven’t demonstrated why this would be true. Read the Victor Stenger link I provided in the post.